Cannot migrate an Exchange 2013/2016 mailbox after it has been migrated earlier
This week we had been performing a migration from Exchange 2013 to 2016. This process included a migration of mailboxes from Exchange 2013 database availability group to a new DAG on Exchange 2016 servers. As you may know, there is no way to add Exchange 2016 servers into an existing DAG, created on Exchange 2013 servers. So, I had been performing these migrations and found out that a correct target database was not set for one mailbox. This mailbox migrated to a second database located on Exchange 2013. When I noticed that mistake I tried to move the mailbox to a correct database, but I did not succeed. I created a new mailbox move request using ECP targeting it to a correct database. This move request have started an initialization process and ended up with a message that 0 mailboxes were synced and 0 were finalized. The highlighted line stands for "Number of mailboxes finalized". I have migrated all the remaining mailboxes and was in need to solve that issue to decomm...